Cervical preparation before D&E reduces the risk of cervical laceration and uterine perforation compared to mechanical dilation. (1-2) Laminaria has been the standard method of preoperative cervical preparation for many years.(3) Later in the second trimester, serial laminaria placement provides greater dilation than one-day treatment,(4) yet limited access to second trimester abortion services has led providers to investigate alternatives that act more quickly. Misoprostol is widely used prior to second trimester D&E.(5) Early in the second trimester overnight laminaria provides better dilation than same-day misoprostol.(6) Buccal misoprostol when given 60-90 minutes preoperatively as an adjunct to laminaria does not improve cervical dilation among women 13-19 weeks, but does improve dilation among women 19-20 weeks gestation.(7) Earlier in gestation, misoprostol likely needs longer to work. In the first trimester, misoprostol has no effect on cervical dilation after 60 minutes,(8) yet multiple studies show benefit after 3 hours.(9-10) First trimester cervical preparation studies also suggest mifepristone may be more effective and better tolerated than misoprostol.

We propose a double-blind, three arm randomized controlled trial comparing laminaria alone, laminaria plus buccal misoprostol given 3 hours preoperatively and laminaria plus oral mifepristone given at the time of laminaria placement for women 16 to 23 6/7 weeks gestation undergoing D&E. Our primary outcome is D&E procedure time. Secondary outcomes include comparisons of initial cervical dilation, ability to complete the D&E on the first attempt, need for mechanical dilation and ease of dilation if required, complications, pain, side effects and patient and provider acceptability. We estimate a total of 300 women are required to have 80% power to detect a 2 minute difference in procedure time between the two medication arms and between each medication arm and the placebo group within two cohorts: 16-18 6/7 weeks (N=150) and 19-23 6/7 weeks gestation (N=150).(11-12)